Reciprocating engine.



E. A. PERKINS.

RECIPROCATING ENGINE.

APPLICATION FILED FEB. 6, 190s.

Patented Deo. 30, 1913.

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E. A. PERKINS. Y

REGIPROGATING ENGINE.

APPLICATION FILED IBB. 190e'.

Patented Dee. 30, 1913.

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RECIPBOCATING ENGINE.

l Specication of Letters Patent; Application led February 6, 1908. Serial No. 414,486.

Patented Dec. 30,1913.

To all whom t may concern Be itknown that I, EDWIN A. PERKINS, of Cambridge, in thefcounty of Middlesex and State of Massachusetts, a citizen of the United States, have invented a new and uselful Improvement .in Reciprocating Engmes, of which the following. is a specificat1on.

My invention relates to a reciprocating engine or tool and especially to that type of engine or tool employing reciprocating pistons connecting with one another and reciprocated by the admission' of-luid pressure thereto. l

The essential object of my'invention is to provide an engine or tool of the above character having a simple and compact structure in which Athe pressure is admitted at a point between the respective pistons and directed to alternately operate upon the backs of the respective pistons for alternately impelling and retracting the same, or, in other words, effecting a reciprocating motion thereof and which is especially adapted for drills for deep boring. My invention can best be seen and understood by reference to thedrawings in which there -is shown an embodiment thereof used in connection with a drill, the drill being shown for purposes of illustration attached to one of the pistons.

' In the drawings Figure v1 is a vertical section ofthe engine. Figs. 2, 3, 4 and 5 3.5 are enlarged vertlcal'secti'ons of the engine showing the different positions assumed thereby during the operation thereof. Figs. 6, 7 and' 8 are sections taken, respectively, on lines 6-,6,7-7 and 8-8 of Fig. 1.

A is a casingfform'ing the body ofthe engine. The casing is chambered, there being formed within it the respective piston chambers B,.B1, connecting which is an opening or passage a. Located within the respective chambers B, B1 are pistons C, C1. The piston C will hereinafter sometimes be termed the withdrawing piston and the piston C1 the drivin piston which it will be 4obed to it, for purposes of illustration, a Adrill D. The twopistons are connected by a piston rod E which extends through the opening or passage a. The

combined pistons' arel capable of a recipro eating movement in their respective chambers, the extent of these chambers and length of the connecting piston rod permitting of such movement. During their rebers.

ciprocation the pistons are ided by the walls of their respective cham ers.

Referring now to the operation ofthe pistons, it will be observed that the adaptation and arrangement ofthe parts are such that a y aperture o r chamber is pressure-receiving formed between the respective piston cham- This aperture in thel construction shown is formed between the vwall of the aperture a and the piston rod extending through this dpassage, the central portion of' the piston ro E being smaller .than the bore of said passage, thereby leavingaportion of the passage open around the rod forming the pressure-receiving aperture. Only the central portion of the piston rod is made smaller than the bore of the passage through which it extends for as the piston rod at either end thereof approaches the respective pistons the rod is made of substantially the same size' as the bore of the passage a through which it extends or lso as -to fit snugly therein without interfering with the longitudinal movement of the rod through the passage a during the reciprocation of the pistons. Inasmuch as the pressure-receiving aperture left between the piston rod and wall of the passage a forms actually a part of the passage a it will hereinafter vbe referred toas the pressure-receiving aperture a.4 Into this' aperturethe pressure is initially admitted for reciprocating `the respective pistons through a 'supply passage F which connects with the aperturea by a by passage f.

The pressure from the pressure-receiving aperture a is alternately supplied to the backs ofthe respective pistons for effecting a reciprocating movement thereof as follows: There are provided through the wall of the casing two passages b, b1. The p assage b extends from the .pressure-receiving aperture a at one end thereof through the wall of the casin and. connectsl with the chamber Bback oft passage b1 extends from the other end of the pressure-receiving aperture a through the wall of the casing and connects with the lchamber B1 back of the piston C1 located within this chamber. It is through these passages b, 61 that the pressure is supplied to the backs of the respective pistons;

to the piston- C for effecting a retracting movement of the engine and to the piston C1 for 'effecting a driving movement thereof. There also connects with the pressure- 1 land main exhaust passae receiving aperture a an exhaust passage G. This passage-G connects with the aperture a by separate by passages g, g1, which are so arranged that both by passages w,ill not be in simultaneous communication with the yaperture a, but will alternately have com- In order that the fluid pressure may bey directed from the pressure-receiving aperture a to enter the piston chambers B, B1, through the passages b, b1, and exhaust therefrom through the by' 4 1n proper alternation, the piston rod is provided with a series of enlargements or rings e, e1, e2, e3 which move vwith the piston rod and in so far as my invention is concerned form a Y part thereof although in .practice these rings may be 1n the nature of auxiliary rings or washers applied to said rod. The p articular arrangement of these enlargements or rings in -their relationship 4to the other passages can only be understood in the light of the operation of the engine.

fIt will he assumed that the engine 4is in lthe position shown in Fig. 2, or at the end,

of its retraction, in position to be impelled by the pressure for effecting its Working stroke. At this time the arrangement of the enlargements or rings e2 is such that ythey will lie above the pressure inlet 'passage f on which account the pressure cannot :pass 'by reason ofthe enlargement of the rod above these .rings through the aperture a, but will be directed to pass downward through the' aperture and enter the passage b1 and chamber C1 back of ;the piston\B1 therein,.thereby acting to drive down Athe piston and effect lthe working stroke of the engine. At this same time the pressure cannot enter the exhaust g1 by reason ou?.- the fact that the piston rod between the entrance into the passage 4b1 and the chamber 'C1 A1s made of sufficient size to fill the pressurereceiving aperture a and so close the exhaust. The effect of this air pressure in the 'passage b1 is illustrated in Figs. 3, 4 and 5, Fig. 3 showing the first effect where 'the piston C1 has been driven down part way carrying with it of course the piston C and the piston rod Eavhich connects the two pistons as well as the enlargements or rings e, e1, e2 and e. In Fig. 4 there is illustrated assages g, g1,

a further movement of the piston and the Aparts connected thereto .and in Fig. 5 the extreme movement. 1t will be noted that .-in Fig. 4 the ring e2 is just passing the opening of. the aperture in the passage f and m Fig. 5 the rings e? and e3 have passed the opening f. During this period it will be noted that, presupposing the pistons have been lifted by pressure on the rear of the piston C 'and that the chamber B is f ull of compressed air, 'this compressed air will 'have an outlet fthrough the passage b, the aperture a and the exhaust passage g, this relieving the immediate pressure until such. time as the enlargement e closes the-outlet g as shown in Fig. 3 after which time, during the further descent of thering e the air has an opportunity of escaping through the upper part ofthe aperture a Where it connects with the chamber 'B and down :through 'the said aperture and out through the outlet g.

When 'the parts have reached the position shown in Fig. 5 a similar situation yis presented to that above described, viz The ring e1 has passed the outlet aperture g1 so that the pressure in the chamber B1 is relieved,

Vthis pressure expanding itself downward through the passage b1 into the aperture a1 around the piston rod E and down and out through the exhaust aperture g1 and the exhaust passage G. When in this position, however, it will Ibe also noted that the "inletf now connects'with'that portion of the aperture a which tis above 'the enlargement yor ring e2 so lthat the pressure is applied vthrough the 'passagetgto the under side of the piston C thus tending to lift it and -this lifting by direct :pressure continuing until the ring e lhas passed the opening .f when expansion and the momentum -of fthe piston will carry the piston back Atothe originalv position shown 'in Fig. 2, lthe air `in Ythe chamber B1 during this period being exhausted as above described rst through lthe passage b1, aperture a and outlet -g1 and then after the ring e1 has passed 'the outlet g1, through .the passage :around the fpiston'rod below the rin e1. This returns the lparts into the l-posit1on shown fin Fig. Q'and the operation is repeated. v

'In 'addition -'I have shown in Fig. 1 ate tached to the top of the casing A a shell K through which the passages -F and G are continued tothe top thereof as above described. This shell also contains a chamber K1. .Down through `the -side of this shell fand through the casing-.as well is a passage J which is connected'with 'the aperture va by the passage j so that there is practically a continuous leakage of compressed air AThe top of the shell K is 4provided with openings lc and the ciossbar L between these openings provides a lmeans for attaching the )ars to Jthe apparatus. This portion of the .apparatus will 'not be further described when the engine is used for driving a drill.,

I have described above the simplest form of my invention known to me,- but it may be otherwise embodied or applied to other uses than that shown in the drawings.

Vhat I claim as my invention is l. A reciprocatin engine having a body or casing and forme 'therein separate chambers with a passage connecting said cham-- bers, pistons' located within said respective chambers and a piston rod connecting said pistons by extending through said passage,

said rod for a portion qf its length having a diameter less Ythan the diameter of said passage leaving an opening bet-Ween the wall of said passage and said rod, said engine and part-s thereof being also provided with a iluid inlet passage communicating with said opening and with'by-passages in constant communication with saidopening on opposite sides of said inlet passage and leading to the adjacent ends of said chambers, and with exhaust passages connecting with portions of said opening on opposite sides of said inlet passage, said par-ts being adapted and arranged also whereby Huid pressure admitted as aforesaid may be alternately 'supplied to said opening on opposite sides of said linlet passage and to the adjacent ends of said respective chambers and exhaust therefrom through said opening and said ex'- haust passages as said exhaust passages become successively uncovered during the reciprocation of said pistons.

2. Areoiprocatin-g engine having a body lor casing and formed therein separate chambers with )a passage connecting said chambers, pistons located within said respective chambers and a^piston rod connecting lsaid pistons by extending through said passage, said piston rod for a portion of its length having a diameter less than the diameter of said passage leaving an opening between the wall of said passage and said rod, saidl'engine and parts thereof being also provided with a fluid inlet passage communicating with said opening, and with by-passages on opposite sides of said fluid inlet passage in constant communication with said opening andleading to the adjacent ends of said chambers, and with exhaust passages on opposite sides of said fluid inlet -passage removed from` one another a distance longer than the length of the opening between the wall of said passage and the contracted portion of said rod as aforesaid and connecting with some portionthereof as said pistons are reciprocated', said parts being adapted and arranged also whereby fluid pressure admitted as aforesaid may be alternately supplied to said opening on opposite sides of said inlet passage and to the adjacent ends of said respective chambers and exhaust therefrom through said opening andV said exhaust passages as said exhaust passages become successlvely uncovered during the reciprocation of said pistons.

EDWIN A. PERKINS. Witnesses:

y M. E. F LAHERTY,

F. F. PHILLIPS, Jr. 

